Crown or root gall of grape is one of the most important bacterial diseases of vineyards in Turkey. Eighty-one vineyards in the Aegean Region were surveyed and 31 gall samples were collected between 2009 and 2011. A total of 16 of R. vitis isolates were identified and classified by PCR using species-and opine type-specific primers. Pathogenicity was determined by inoculating plants of sunflower and a highly virulent strain was used to determine the sensitivity of the most common rootstocks (10) and grapevine cultivars (31) in Turkey for two years. Two-year old rooted grape cutiings were artificially inoculated with bacterial suspension (10(7)cfu/ml). Plants were maintained in climate rooms (at 18-24 degrees C temperature, 80% relative humidity, 12 h light/dark) and gall diameters and weights were measured after 3 months. At the end of the study, all the isolates obtained from this region were determined to cause octopin/cucumopine type opin synthesis. Ramsey and 1613-C were the most tolerant rootstocks while 420-A and 41-B were the most susceptible to R. vitis. On the other hand, Sultan 1, Sultana Seedless (Type 4) and Sultan-7 (from the Sultana Seedless group) and Mevlana, Red Globe and Pembe Gemre (6th, 11th and 12th clones) were found to be the most susceptible while Bornova Misketi was the most tolerant grape cultivar.